1. Field of the Invention
The present invention relates to shift apparatuses for industrial machining, and particularly to workpiece shift apparatuses used for punch presses.
2. Related Art
Various electronic devices are ubiquitous in modern society. For example, computer servers and routers pervade the business world. Many such electronic devices generate a lot of heat during normal operation. This can deteriorate their operational stability and damage associated electronic device. Thus vents are defined in such electronic devices for facilitating air flow and heat dissipation.
Conventional means for machining vents in a workpiece comprise, for example, laser machining and conventional punch machining. Laser machining is costly and is therefore not widely used. Conventional punch machining requires manual manipulation to control movements of workpieces. This is slow and unsafe. Furthermore, the workpieces are liable to be imprecisely machined.
A workpiece shift apparatus for a punch press which overcomes the above-mentioned problems and shortcomings is desired.
Accordingly, an object of the present invention is to provide a workpiece shift apparatus which can readily and precisely move workpieces on a punch press.
To achieve the above-mentioned object, a workpiece shift apparatus in accordance with the present invention comprises a bottom plate, a middle plate slidably attached on the bottom plate, and a top plate slidably attached on the middle plate. The bottom plate includes a first large piston cylinder installed thereon. The first large piston cylinder has a first large piston rod that is extendable in a first direction. A first small piston cylinder is installed on a first supporting block, and the first supporting block is connected with an end of the first large piston rod. The first small piston cylinder has a first small piston rod. The first small piston rod is extendable in a second direction that is perpendicular to the first direction. A first handspike is connected to and movable with the first small piston rod. A first pushing plate is slidably attached on the bottom plate. The first pushing plate defines a plurality of first cutouts in one edge thereof, and forms a plurality of arcuate first steps on an opposite edge thereof. When the first pushing plate is moved in the first direction, the first steps push the combined middle plate and top plate in the second direction. The first handspike is sequentially engaged in the first cutouts, to allow the first pushing plate to be sequentially moved in the first direction. The combined middle plate and top plate can thereby be sequentially pushed in the second direction.
The middle plate includes a second large piston cylinder installed thereon. The second large piston cylinder is oriented perpendicular to the first large piston cylinder. The second large piston cylinder has a second large piston rod which is extendable in a third direction that is opposite to the second direction. A second small piston cylinder is installed on a second supporting block, and the second supporting block is connected with an end of the second large piston rod. The second small piston cylinder is oriented perpendicular to the first small piston cylinder. The second small piston cylinder has a second small piston rod. The second small piston rod is extendable in the first direction. A second handspike is connected to and movable with the second small piston rod. A second pushing plate is slidably attached on the middle plate, and is oriented perpendicular to the first pushing plate. The second pushing plate defines a plurality of second cutouts in one edge thereof, and forms a plurality of arcuate second steps on an opposite edge thereof. When the second pushing plate is moved in the third direction, the second steps push the top plate in the first direction. The second handspike is sequentially engaged in the second cutouts, to allow the second pushing plate to be sequentially moved in the third direction. The top plate can thereby be sequentially pushed in the first direction.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of preferred embodiment of the present invention with attached drawings, in which: